Aliphatic epoxide-amine adducts with substantial side-chain branching, process for their preparation, and their use

ABSTRACT

Epoxide-amine adducts having a proportion by mass of at least 20% of aliphatic epoxide or amine units which comprise at least one tertiary or quaternary carbon atom are disclosed. The adducts are employed as binders for coatings of relatively high environment-friendliness, if desired, for example, in a mixture with other hydroxy-functional binders, and as reactive component in corresponding adhesive compositions and sealing compounds.

This application is a divisional of application Ser. No. 08/641,733,filed May 2, 1996 U.S. Pat. No. 5,929,272.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to epoxy amine adducts having substantialside chain branching, processes for making them and to binders thatemploy these adducts. The binders are environmentally safe, have a lowsolvent content and can be used in pigmented and unpigmented systems.

2. Description of Related Art

To protect the environment, it has been an objective to reduce theemission of organic compounds, especially the amount of solvent. Thesolvent content of adhesives, sealing compounds and coating materialsmust be reduced in the future from the values which are still customarytoday, on the basis of statutory regulations (e.g. VOC (Volatile OrganicCompounds) regulations in the USA and Great Britain and "TA Luft"[German air pollution control regulations] in Germany).

This county-specific statutory pressure is exerted with varying degreesof severity in different countries. The statutory authority permitsdifferent evaluations (individual considerations, combinedconsiderations), which impel the producer of such coating, adhesiveand/or sealing products to provide new and different levels of technicalperformance. This has reached the extent where the usually highperformance level of such products must on environmental grounds be cutback to a minimum level.

Clearcoats as unpigmented systems are employed in automotiverefinishing, for example, as the topmost coat. Their function typicallyis to protect the pigmented, lower coat (basecoat) against mechanicalstress, against the effect of weathering and against dirt, and toprovide the overall coating system with the necessary gloss. Theseclearcoats predominantly have been formulated with polymeric binderswhich have usually been employed simultaneously in pigmented topcoats aswell. The severe VOC regulations, however, force the producer of rawmaterials to formulate this clearcoat separately, in some cases, withthe addition of low molar mass polyols, as a "blend system" (EP-A-0 588314, EP-A-0 129 124 and U.S. Pat. No. 5,098,956).

Various methods can be used to reduce the solvent content. For example,polymeric binders of extremely low molar mass are used, alone or inblends with binder components of higher molar mass. Highly complexbinder systems are known, for example, which comprise mixtures ofoligomeric caprolactone polyols, i.e. polyester polyols with acrylatepolyols and/or acrylate star polymers (WO 92/22618). Certain organiccompounds, for example, aspartic acid derivatives, aldimines, ketiminesor oxazolidines (EP-A-0 470 461, EP-A-0 403 921, U.S. Pat. No.5,214,086, and Robinson et al., "High performance polyurethane coatingssystems utilizing oxazolidine based reactive diluents" 21st HigherSolids and Waterborne Coatings Symposium (February 1994) New Orleans,La., USA) also are described as reactive diluent systems or as solebinders.

The maximum amount of volatile organic constituents that are permittedfor the clearcoat in automotive refinishing in California, for example,is 3.5 lb/gal (0.42 kg/dm³), i.e. a mass fraction of solids of about 59%in the coating material (DIN 53 211, 4 mm cup, 21 s flow time at 23°C.). The restrictions become more severe when a conventional basecoat isapplied: the overlying clearcoat must not exceed a VOC limit of 2.1lb/gal (0.25 kg/dm³, i.e. a mass fraction of solids of about 75% ).Important processing properties then are lost when extremely low molarmass polyols are used, for example, the rapid drying of the clearcoat.When the above-mentioned organic compounds are employed, there is noguarantee of a long pot life (processing time). In addition, partialdissolution of the basecoat or skinning, in some cases cloudiness, andgas-escape defects are observed with the rapid reactive diluent systems.The original aim of enabling the use of these binders in pigmentedsystems as well as unpigmented systems, however, cannot be achieved inthis case.

Thus, there exists a need to develop environmentally friendly bindersystems having a low solvent content which give rise to rapid drying, along pot life, little or no partial dissolution of the basecoat, and noskinning, cloudiness or gas-escape defects. There also exists a need toprovide binder systems that are universally useful in unpigmented andpigmented systems. Moreover, there exists a need to be able to use thesesystems in environmentally friendly adhesives and sealing compounds.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide aliphaticepoxide-amine adducts, processes for their manufacture and their use inbinder systems which do not suffer from the aforementioneddisadvantages. It is an additional object of the invention to providethese epoxide-amine adducts, processes for their manufacture and theiruse in binder systems whereby the binder systems are environmentallyfriendly, have a low solvent content, can be dried rapidly, have littleor no partial dissolution of the base coat, have no skinning, cloudinessor gas-escape defects, and which are universally useful in pigmented andunpigmented systems.

In accordance with these objectives, it has surprisingly been found thatthe addition of aliphatic epoxide-amine adducts having specialstructures enables the development of binder systems of this type havingthe properties mentioned above.

In accordance with one object of the invention, there is providedepoxide-amine adducts having at least 20% by mass of aliphatic epoxideand/or amine units which comprise at least one tertiary or quaternarycarbon atom. The mass fraction of such units is preferably at least 25%,particularly preferably at least 30%.

In accordance with additional objects of the invention, there areprovided methods of making epoxide-amine adducts having substantialside-chain branching, and to binders employing these adducts. Thisinvention therefore provides, in addition to the preparation of theepoxide-amine adducts with substantial side-chain branching, bindersystems which comprise these adducts and environmentally friendlycoating systems formulated therefrom. The invention further provides theuse of these epoxide-amine adducts in environment-friendly coatings,adhesives and sealing compounds.

Further objects, features and advantages of the invention will becomeapparent to those skilled in the art from the detailed description ofthe preferred embodiments that follows.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The expressions "chain-branched units" or "branched" as they are usedherein denote those units having at least one tertiary or quaternaryaliphatic carbon atom. Throughout this description, the expression"extremely low" or "low", insofar as they refer to the molar mass of theepoxide-amine adducts of the invention denotes a weight-average molarmass of less than about 3,000 g/mole. The expression "low" used inconnection with solvent content refers to mass fractions of solvent ofless than 35%.

With the high-solids, polymer-based binder systems, it is possible toachieve clearcoat solids contents of up to about 67% by mass. Masssolids contents higher than this usually can be obtained only with theaid of low molar mass ("monomeric") organic compounds of definedfunctionality. Compounds which comprise structural units similar tothose of the low molar mass polyacrylate resins which can be employed incustomary high-solids systems should be capable of homogeneous mixingwith these resins (reactive diluent system) and, on application, shouldimprove the drying properties. In this way, it should be possible toachieve the aim of a solids content of up to about 75% by mass."High-solids systems" in this context are systems having a mass fractionof solids in excess of about 50%.

Any branched epoxide-amine adduct can be used in the present invention.Branched epoxide-amine adducts which are particularly suitable for theinvention can be prepared by reacting a) aliphatic and/or cycloaliphaticmonoepoxides having 7 to 33 carbon atoms and b) amines having at leasttwo primary or secondary amino groups and 2 to 30 carbon atoms, whoseprimary or secondary amino groups are not attached directly to anaromatic structure, wherein at least 20% by mass of the monoepoxides isselected from aliphatic and cycloaliphatic monoepoxides having at leastone tertiary or quaternary carbon atom. Epoxide-amine adducts that areprepared by use of the mono-epoxides selected from glycidyl esters ofα-alkylalkanemonocarboxylic acids and glycidyl esters ofα,α-dialkylalkanemono-carboxylic acids having in each case 8 to 21carbon atoms in the esters, are particularly preferred.

Further suitable epoxide-amine adducts can be prepared by reacting a)aliphatic and/or cycloaliphatic diepoxides having 8 to 50 carbon atomsand b) primary or secondary monoamines having 4 to 30 carbon atoms,whose amino groups are not attached directly to an aromatic structure,wherein at least 20% by mass of the monoamines is selected frommonoamines having at least one tertiary or quaternary carbon atom.Epoxide-amine adducts that are prepared using the diepoxides selectedfrom the diglycidyl ethers of dihydric aliphatic alcohols and thediglycidyl esters of dibasic aliphatic carboxylic acids having 8 to 18carbon atoms in the ethers and, respectively, 12 to 42 carbon atoms inthe esters are particularly preferred.

Additional useful epoxide-amine adducts of the present invention can beprepared by reacting a) aliphatic and/or cycloaliphatic monoepoxideshaving 7 to 33 carbon atoms and b) monoamines selected from primary andsecondary monoamines having 4 to 30 carbon atoms, whose amino groups arenot attached directly to an aromatic structure, wherein at least a % bymass of the monoamines is selected from monoamines having at least onetertiary or quaternary carbon atom and at least b % by mass ofmonoepoxides is selected from aliphatic and cycloaliphatic monoepoxideshaving at least one tertiary or quaternary carbon atom, a and b eachbeing greater than 0 and the sum of a and b being at least 20,preferably at least 25 and, with particular preference, at least 30.Epoxide-amine adducts that are prepared using the monoepoxides selectedfrom glycidyl esters of α-alkylalkanemonocarboxylic acids and glycidylesters of α,α-dialkylalkanemono-carboxylic acids having in each case 8to 21 carbon atoms in the esters are particularly preferred.

The epoxide-amine adducts according to the invention preferably have atleast one, and a maximum of two, secondary OH group(s) and at least onesecondary (in the case of primary amines as precursors) or tertiary (inthe case of secondary amines as precursors) amino group per molecule.Any remaining amino groups, if polyamines are used, with monoexpoxides,remain unchanged or are similarly converted into secondary or tertiaryamino groups, depending on the stoichiometry. It is known thatepoxide-amine adducts based on glycidyl esters ofα,α-dialkylalkanemonocarboxylic acids with isophorone-diamine can beemployed for extending the chain length of isocyanate-terminatedurethane prepolymers (JP 02251516 A2), with only the amino groupsreacting and the secondary OH groups being retained. However, it was notknown that these compounds could be employed as reactive diluents withboth the amino groups and the hydroxyl groups reacting. These definedfunctional compounds, which can be used as a mixing component withpolyisocyanates, lead simultaneously to polyurethane and to polyureastructures, the latter guaranteeing rapid curing and high pendulumhardness.

Owing to the high weather stability and high reactivity, the adductspreferably are prepared using aliphatic, sterically hindered or cyclicamines. Those skilled in the art will recognize that sterically hinderedin this context denotes the presence of branched aliphatic structures orcycloaliphatic structures or aromatic structures. Examples of suitablediamines include neopentanediamine (2,2-dimethyl-1,3-propanediamine),1,2-diamino-2-methyl-propane, diamino-cyclohexanes, such as1,2-diaminocyclohexane, and 1,4-diaminocyclohexane, xylylenediamines,such as m-xylylenediamine, 1,3-bis(aminomethyl)cyclohexane,1-amino-2-aminomethyl-3,3,5(3,5,5)-trimethylcylopentanetriacetone-diamine(4-amino-2,2,6,6-tetramethylpiperidine),1,8-diamino-p-menthane,isophoronediamine(3-aminomethyl-3,5,5-trimethycyclohexlamine),4,4'-diaminodicyclohexylmethane,3,3'-dimethyl-4,4'-diamino-dicyclohexylmethane,3(4),8(9)-bis(aminomethyl)tricyclo-[5.2.1.0²,6 ]decane. Examples ofsuitable monamines include ethylamine, butylamine, isobutylamine,tert-butylamine, hexylamine, cyclohexylamine, 2-ethylhexylamine, Primene81R® (from Rohm & Haas, mixture of t-alkyl-substituted primary amines).It also is possible to employ mixtures of these amines.

Suitable epoxide-amine adducts also can be prepared from aliphaticdiepoxides and aliphatic, branched monoamines, as is known fordeposition coating materials in aqueous epoxide-amine chemistry andoften is used as a principle of crosslinking reactions.

The aliphatic diepoxides useful in the invention can be selected fromthe esters and ethers of glycidyl alcohol with aliphatic dicarboxylicacids or aliphatic diols, respectively. Examples include ethylene glycoldiglycidyl ether and butanediol diglycidyl ether; suitable esters arediglycidyl esters of (cyclo)aliphatic branched or unbrancheddicarboxylic acids having 2 to 40 carbon atoms, for example, thediglycidyl esters of succinic acid, adipic acid, hexahydroterephthalicacid or dimeric fatty acids. For clearcoat applications, diglycidylethers are less preferred since, when used for exterior applications,they usually possess a poor weather resistance. Suitable monoaminesusually contain at least one tertiary or quaternary carbon atom and atotal of from 4 to 30 carbon atoms. Examples of useful monoaminesinclude isobutylamine, tert-butylamine, 2-ethylhexylamine and Primene81R® (from Rohm & Haas, mixture of t-alkyl-substituted primary amines).

The epoxide-amine adducts according to the invention can be prepared inany suitable manner, for example, by in a conventional manner, i.e. notin an aqueous medium. Then, the initially prepared epoxide-amine adductshaving up to four functional groups (secondary hydroxyl groups,secondary or tertiary amino groups), can be diluted if desired inorganic solvents or solvent mixtures and then subjected to crosslinking.

The reaction products of monoepoxide and diamine or monoamine, or ofdiepoxide and monoamine are readily obtainable with or withoutcatalysts. Such products typically possess a weight-average molar massof below 3000 g/mol, especially below 2000 g/mol and, in particular,below 1500 g/mol. The addition of these compounds to coating systems,for example, mixtures of two or more polyols, i.e. polyacrylate polyolsor polyester polyols with or without the addition of known reactivediluents, pure polyols ("sole binders") and combinations of thesepossibilities leads to mass fractions of solids of up to about 75%. Thistarget can be achieved in any case on the use of the epoxide-amineadducts alone with appropriate curing components.

The epoxide-amine adducts according to the invention can be prepared bythe addition of the amine onto the epoxide at elevated temperature. Theamine preferably is taken as an initial charge and reacted with theepoxide, usually without a catalyst, under an inert gas atmosphere attemperatures from about 50 to 150° C. until substantially no epoxide ispresent. Preferably, the amine is reacted with the epoxide until theepoxide is no longer present. The adducts prepared can be diluted to aselectable extent with any solvents or solvent mixtures, the choice ofwhich is unrestricted.

The binders or binder mixtures of extremely low molar mass can, byaddition of these epoxide-amine adducts, be increased in their massfraction of solids in the coating material from about 67 to about 71%(DIN 53 211, 4 mm cup, 21 s, 23° C.). In accordance with the invention,these binders also can be increased in reactivity. As sole binders,these epoxide-amine adducts of the invention are extremely reactive andcan be used together with appropriate curing agents in two-componentadhesives or sealing compounds.

The use of such adducts as sole binders in coatings technologypresupposes the slowing down of the curing reaction. Retarding(delaying) additives include, for example, organometallic compounds,electron-deficient compounds, certain acids or salts. Examples ofsuitable organometallic compounds are tin compounds, such as dibutyltindilaurate, dibutyltin diacetate and dibutyloxotin, and also zincoctoate, or zirconium compounds. Examples of useful electron-deficientcompounds include boron trifluoride, aluminum compounds andcarbocations. Acids useful in the invention include, for example, formicacid, acetic acid, perchloric acid or trichloroacetic acid. Salts, suchas triphenylmethyl perchlorate, tropylium hexachloroantimonate or acetylperchlorate, also can be employed.

Such compounds typically are premixed with the epoxide-amine adducts,for example, and then form, with the nitrogen atoms of the amino groupsand with the oxygen atoms of the alcohol groups, "chelate-like"complexes which, depending on complex strength, compete with the curingreaction. The mass fractions of solids of such coating systemscomprising the binder adducts of the invention and curing agent usuallyare up to about 75% (DIN 53 211, 4 mm cup, 21 s, 23° C.). In order toslow down the curing reaction, it also is possible to reduce thefunctionality of such epoxide-amine adducts, by subsequently modifyingthem in whole or in part. Such modifications can comprise protectinggroups (temporary) or can be permanent. For example, the secondary aminofunctions can be inactivated by reaction with isocyanate compounds ofwhich each molecule contains on average from 0.8 to 1.5 free NCO groupsand at least one tertiary amino group.

As examples of temporary protecting groups, the secondary alcohol andamine function can be reacted with aldehydes or ketones. Theoxazolidines formed can easily be cleaved again using atmosphericmoisture/water to form the original functionalities, which then areavailable successively for curing reactions. Such protectedepoxide-amine adducts are likewise a part of the invention and arehenceforth included under the term epoxide-amine adducts according tothe invention.

The epoxide-amine adducts according to the invention, in combinationwith polyacrylate polyols, are particularly suitable for coatingapplications in one- and two-component systems, especially forhigh-solids systems, i.e. for solvent-containing mixtures having a highsolids content. In these combinations, preference is given to employingmixtures comprising mass fractions of

a) from 0.1 to 99.9% of hydroxyl-containing copolymers and

b) from 99.9 to 0.1% of the epoxide-amine adducts according to theinvention.

Examples of hydroxyl-containing copolymers include polyacrylates orpolyesters. Polyester-modified acrylate resins also are included here.Particularly suitable hydroxyl-containing copolymers can be selectedfrom:

aa) copolymers which are obtainable by copolymerization of at least twovinyl monomers of which at least one comprises at least one hydroxylgroup;

ab) copolymers which are obtainable by copolymerization of at least twovinyl monomers of which at least one has at least one acid group andwhich are reacted, before, during or after polymerization, with at leastone compound which reacts with the acid groups to form an ester with theformation of at least one hydroxyl group; and

ac) copolymers which are obtainable by copolymerization of at least twovinyl monomers of which at least one has at least one hydroxyl group andwhich are reacted, before, during or after polymerization, with at leastone compound which reacts partly or completely with the hydroxyl groupsto form an ester with the formation of at least one hydroxyl group.

The copolymers of aa) can customarily be prepared in a free-radicalsolution polymerization. Products based on maleic esters can also beprepared in a bulk polymerization, i.e. without solvents. In copolymersof type ab) or ac), the additional freedom of the choice ofpolymerization method, solution or bulk polymerization, is afforded bythe addition of specific compounds having relatively high boilingpoints. Examples of these compounds in the case of type ab) includeglycidyl esters or glycidyl ethers and, in the case of type ac), includelactones.

Particular preference is given to those mixtures in which theepoxide-amine adducts according to the invention are added to a mixtureof hydroxyl-containing copolymers which each have a hydroxyl number offrom 10 to 250 mg/g and of which at least one has a weight-average molarmass of more than 3500 g/mol and at least one has a weight-average molarmass of below 3500 g/mol.

Examples of suitable solvents for the products obtained in accordancewith the invention include aliphatic, cycloaliphatic and aromatichydrocarbons, such as alkylbenzenes, for example xylene, toluene;esters, such as ethyl acetate, butyl acetate, acetates with longeralcohol residues, butyl propionate, pentyl propionate, ethylene glycolmonoethyl ether acetate, the corresponding methyl ether acetate orpropylene glycol methyl ether acetate; ethers, such as ethylene glycolacetate monoethyl, monomethyl or monobutyl ether; glycols; alcohols;ketones, such as methyl isoamyl ketone, methyl isobutyl ketone;lactones, and mixtures of such solvents. Other solvents which can beemployed include reaction products of lactones with glycols or alcohols.

The present invention additionally relates to coating compositions whichcontain the epoxide-amine adducts according to the invention as bindercomponent. In this context, it is preferred that the coatingcompositions comprise at least one epoxide-amine adduct according to theinvention as a reactive diluent, and at least one furtherhydroxy-functional binder and at least one curing agent. These reactivediluent systems can be cured in the presence of suitable crosslinkingagents without heating or at elevated temperature.

Any desired curing agents can be used in accordance with the presentinvention. Compounds which are suitable as the curing component in thesecoating compositions include amino resins, polyisocyanates, or compoundscomprising acid and/or acid anhydride groups, individually or incombination. The crosslinking agent in each case can be added in aquantity such that the ratio of the number of OH or NH groups present inthe binder or binder system to the number of reactive groups present inthe crosslinking agent is between 0.3:1 and3:1.

Amino resins suitable as curing components preferably are urea resins,melamine resins and benzoguanamine resins, individually or in a mixture.These are etherified products of the condensation of urea, melamine orbenzoguanamine with formaldehyde. Suitable mixing ratios usually are inthe range of from 50:50 to 90:10 hydroxyl- or amino-containing bindersystem to amino resin crosslinking agent, based on the mass of the solidresin. Appropriate phenolic resins and derivatives thereof can also beemployed as curing agents. In the presence of acids, for example,p-toluenesulfonic acid, these crosslinking agents lead to curing of thecoating. Hot curing can be undertaken in a customary manner attemperatures of from 90 to 200° C. in, for example, from 10 to 30minutes.

Polyisocyanates also are suitable for curing the products according tothe inventor with crosslinking, especially at moderate temperatures orat room temperature. Suitable polyisocyanate components include inprinciple all those aliphatic, cycloaliphatic or aromaticpolyisocyanates known from polyurethane chemistry, individually or inmixtures. Highly suitable examples are low molar mass polyisocyanates,for example hexamethylene diisocyanate, 2,2,4- and/or2,4,4-trimethyl-1,6-hexamethylene diisocyanate, dodecamethylenediisocyanate, tetramethyl-p-xylylene diisocyanate,1,4-diisocyanato-cyclohexane,1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (IPDI), 2,4'-and/or 4,4'-diisocyanatodicyclohexylmethane, 2,4'- and/or4,4'-diisocyanatodiphenylmethane or mixtures of these isomers with theirhigher homologs. These curing agents are obtainable in a manner knownper se by phosgenization of aniline/formaldehyde condensation products,2,4- and/or 2,6-diisocyanatotoluene, or any desired mixtures of suchcompounds.

It is preferred, however, to use derivatives of these simplepolyisocyanates as are customary in coating technology. These includepolyisocyanates having, for example, biuret, uretdione, isocyanurate,urethane, carbodiimide or allophanate groups, as are described, forexample, in EP-A 0 470 461 . Particularly preferred modifiedpolyisocyanates include N,N',N'-tris-(6-isocyanatohexyl)biuret and itsmixtures with its higher homologs, and N,N',N'-tris(6-isocyanatohexyl)isocyanurate and its mixtures with its higher homologs containing morethan one isocyanurate ring. Compounds which are suitable, in addition tothose previously mentioned, for curing at elevated temperature arecapped polyisocyanates, polycarboxylic acids and their anhydrides.

The epoxide-amnine adducts according to the invention are particularlysuitable for the preparation of high-solids solvent-containingclearcoats and topcoats, and for fillers. In coating compositionsprepared with the epoxide-amine adducts according to the invention, italso is possible for other auxiliaries and additives which are customaryin coating technology to be present. These conventional auxiliaries andadditives include, in particular, catalysts, leveling agents, siliconeoils, plasticizers, such as phosphates and phthalates, pigments, such asiron oxides, lead oxides, lead silicates, titanium dioxide, bariumsulfate, zinc sulfide, phthalocyanine complexes, etc., and fillers, suchas talc, mica, kaolin, chalk, ground quartz, ground asbestos, groundslate, various silicic acids, silicates, etc., viscosity-controllingadditives, matting agents, UV absorbers and light stabilizers,antioxidants and/or peroxide scavengers, antifoams and/or wettingagents, active diluents (further reactive diluents) and the like.

The coating compositions can be applied to the respective substrate byknown methods, for example by brushing, dipping, flow-coating or withthe aid of rollers or blades, but in particular by spraying. They can beapplied under hot conditions, and can, if desired, be brought into anapplication-ready form by injecting supercritical solvents (e.g. CO₂).Binders prepared using the epoxide-amine adducts according to theinvention can be used to provide automotive refinishes, industrialcoatings, wood coatings, plastics coatings, constructional coatings andtextile finishes having outstanding properties. These binders can beused to prepare both intermediate coats and pigmented or unpigmentedtopcoats. For this purpose, the coating materials generally are curedwithin a temperature range from about -20 to +100° C., preferably fromabout -10 to +80° C.

The invention is illustrated in more detail in the examples whichfollow. These examples are meant only to illustrate the presentinvention and not to limit it. In the working examples, all percentagesare mass fractions.

EXAMPLES Example I Preparation of Epoxide-amine Adducts

(Ia.) Preparation of the Epoxide-amine Adducts (without ProtectingGroup)

The diamine listed in Table 1 was charged to a reactor fitted with astirrer mechanism, an inert gas inlet, a heating and cooling system anda metering device, and was heated under an inert gas to the reactiontemperature. Then, the glycidyl ester of anαa,α-dialkylalkanemonocarboxylic acid [e.g. the glycidyl ester ofVersatic 10 acid (trade name: Cardura® E 10, Shell Chemicals)] wasmetered in over the course of 3 hours (Example a) or 4 hours (Exampleb). The post-reaction time was chosen so as to provide an epoxidecontent of 0 (Table 1).

The epoxide-amine adducts were then diluted in appropriate solvents orsolvent mixtures.

                  TABLE 1                                                         ______________________________________                                        Preparation and properties of the epoxide-amine adducts                         Batch                Ia         Ib                                          ______________________________________                                        3,3'-Dimethyl-4,4'-diamino-                                                                      238.4      --                                                dicyclohexylmethane.sup.(1)                                                   Isophoronediamine.sup.(2) -- 170.3                                            Glycidyl ester.sup.(3) 500.0 500.0                                            Reaction temperature 100° C. 120° C.                            Metering time in h 3 4                                                        Post-reaction in h 3 4                                                        Epoxide content in %.sup.a) 0.0 0.0                                         Characteristics: supply form (s.f.)                                                              90% in butyl acetate (BuOAc)                               Viscosity (50% in BuOAc) in mPa · s                                                     12.2       8.6                                               GPC (PS calibration).sup.b)                                                   M.sub.w  in g/mol 1026 910                                                    M.sub.n  in g/mol 944 882                                                     U = M.sub.w /M.sub.n 1.09 1.03                                                Hazen color number (s.f.) 15 33                                               (DIN 53 995)                                                                ______________________________________                                         .sup.(1) Trade name: Laromin ® C260 (BASF, Ludwigshafen)                  .sup.(2) Isophoronediamine (Huls, Marl)                                       .sup.(3) Glycidyl ester of Versatic 10 acid (trade name: Cardura ®        E10, Shell Chemicals, Rotterdam)                                              Determination of the characteristics: Epoxide number (including amine),       amine number and viscosityfor standards see `Analytical Determination         Methods`, brochure from Hoechst AG Kunstharze, 1982 edition                   .sup.a) The epoxide content can be determined by the difference between       epoxide number including amine (with tetrabutylammonium bromide) and the      amine number (primary or secondarywithout tetrabutylammonium bromide).        .sup.b) GPC: M.sub.w, M.sub.n  Millipore ® Waters Chromatography          System 860                                                                    Pump: Waters Model 590, RI detector: Waters Model 410                         Column packing: Waters Ultrastyragel 1 × 1000 Å + 1 × 500     Å + 1 × 100 Å (ångstroms)                                   Solvent: Tetrahydrofuran at 40° C.                                     Flow rate: 1 ml/min, concentration: 1% based on solids                        Calibration: Polystyrene (from PSS, Mainz)                               

As can be seen from Table 1, the epoxide-amine adducts prepared werecompletely reacted (determined by the epoxide content). GPC shows onlythe relative molar mass in relation to the polystyrene calibration. Theproducts were uniform (U≦1.1). The epoxide-amine adducts prepared alsohad very low solution viscosities (50% in butyl acetate).

(Ib.) Oxazolidine Preparation--Epoxide-amine Adducts (with TemporaryProtecting Group)

Epoxide-amine adduct lb (300 g of 90% strength, 0.403 mol) wereinitially introduced into a 500 ml 3-neck flask equipped with a stirrermechanism, an inert gas inlet, a heating system and a metering funnel,and 61.0 g (0.845 mol) of isobutyraldehyde were then metered in withstirring at 55° C. over the course of 4 hours. Then about 50 ml oftoluene were added and the water/solvent mixture (including azeotrope)was distilled off over the course of 2 hours. The colorless to paleyellowish oxazolidine formed, Ic, could be identified by means of FT-IR:

OH band 3450 cm¹ (weak), O-C-N system: triplet 1080-1200 cm⁻¹.

Example II Preparation of the Coating Materials

To prepare the curable coating compositions according to the invention,the components, including at least one epoxide-amine adduct according tothe invention or of a mixture of one or more copolymers with theepoxide-amine adducts according to the invention, were mixed with theauxiliaries and additives, solvents and crosslinking agents in themixing ratio described (Table 2). The mixtures then were adjusted usingfurther diluent, to the spray viscosity of from 21 to 22 seconds withthe flow cup (DIN 53 211, 4 mm, 23° C.). With copolymer components withlow viscosity, this could be carried out without solvent, with heatingto higher temperatures if required.

In a preliminary step, it was desirable to add retarding additives tothe epoxide-amine adducts and to bring the mixtures to an appropriatelyprediluted state. It was advisable to employ the isocyanates inprediluted form as well.

Products of relatively high viscosity were, if the curable mixtures werenot employed as a powder coating, dissolved or dispersed in theabovementioned diluents prior to mixing. In the case of pigmentedsystems, a dispersion step was first carried out in which theappropriate pigments were dispersed together with the epoxide-amineadducts according to the invention or with a mixture thereof withhydroxyl-containing copolymers, with or without the addition of anappropriate, special grinding resin, in a dispersion apparatus ofsuitable construction to form a pigment paste. This paste then wasmixed, as is, or with the addition of further binder which is compatiblewith the other components of the coating system, and was made up withthe addition of further diluents or typical coatings additives. In thiscontext, the pot life and the properties of the resulting films dependedon the process conditions, i.e. on the nature and quantity of thestarting materials, the amount of added catalyst, the temperatureregime, etc. Curing could be carried out discontinuously orcontinuously, for example, by means of an automatic coating apparatus.

                  TABLE 2                                                         ______________________________________                                        Preparation of the high-solids clearcoats with epoxide-amine                    adduct                                                                                              Blend RD RD                                             Binder system system                                                        ______________________________________                                        High molar mass copolymer A2                                                                      20       --                                                 (DE-A 43 24 801), (70%)                                                       Copolymer of application DE-P 20 63                                           195 15 919.5, Example Ia (68.5%)                                              Epoxide-amine Ib * (90%) 20 7                                                 Tinuvin ® 292 0.49 0.43                                                   Tinuvin ® 1130 1.46 1.28                                                  Si oil LO 50% (10% strength) 0.98 0.85                                        Solvent mixture (2:3:10) 14.63 12.80                                          Solvesso ® 100/xylene/BuOAc                                               Desmodur ® N 3390 38.2 36.5 (80%                                            strength)                                                                   Flow cup 21 21                                                                (DIN 53 211) in seconds                                                     Coating designation Coating 1                                                                              Coating 2                                        ______________________________________                                         RD Reactive diluent (epoxideamine Ib)                                         * The epoxideamine adduct was premixed with 0.8 part by weight of a 10%       strength dibutyltin dilaurate solution (10% strength).                        Tinuvin ®292 "HALS" (Ciba Geigy, Basle)                                   Tinuvin ® 1130 UV absorber (Ciba Geigy, Basle)                            Si oil LO 50% Leveling agent (silicone oil from Wacker GmbH, Burghausen)      Desmodur ®N 3390 (Polyisocyanate containing isocyanurate groups (Baye     AG, Leverkusen)                                                               BuOAc Butyl acetate                                                      

After predilution as above, the clearcoats were adjusted precisely to 21s using the same solvent mixture (Solvesso® 100/xylene/BuOAc).

Example III Performance Testing

a.) Clearcoats

The coating systems prepared as in Example II were applied to cleanglass panels using a 100 μm doctor blade, and the applied coatings weretested under the conditions of air drying.

                  TABLE 3                                                         ______________________________________                                        Performance testing of the high-solids clearcoats with                          epoxide-amine adduct                                                            Coating designation Coating 1 Coating 2                                   ______________________________________                                        Appearance          transparent                                                                             transparent                                       Initial/pot life >3 h >6 h                                                    Dust-drying time 20'  41'                                                     Tack-free drying 90' 168'                                                     SC-1 h, 125° C. 68.1% 70.1%                                            Pendulum hardness after                                                       24 h 155  86                                                                   2 d 179 102                                                                   4 d 191 126                                                                  10 d 201 181                                                                  Premium-grade gasoline after 10 d >30 >20                                     in min.                                                                     ______________________________________                                         Pendulum hardnesses according to Konig (seconds)                              SC: Solids content as determined by DIN 53 216                                d: days                                                                       ': minutes                                                               

Summary

As can be seen from Table 3, the high-solids polyacrylatepolyol/extremely low molar mass polyacrylatepolyol/epoxide-amine adductsystem had a solids content by mass whose level (about 68%) was similarto that of the extremely low molar mass polyacrylate polyol as solebinder (coating 3 in the simultaneously filed German application DE-P195 15 919.5, the disclosure of which is incorporated by referenceherein in its entirety), but with good drying and resistance topremium-grade gasoline. The extremely low molar mass polyacrylatepolyol/epoxide-amine adduct system also had an even higher solidscontent by mass, with improved drying, pendulum hardnesses andresistance when compared to the coating designated 3 in thesimultaneously filed application DE-P 195 15 919.5.

b.) Pigmentability of the Coating Materials

The measure used for the pigmentability of the coating materials was the"oil uptake" to the wetting point (Glasurit handbook "Lacke und Farben",10th edition (1969), p. 144 ff.).

A defined quantity (5 to 10 g) of Kronos 2310 white pigment (KronosTitan GmbH, Leverkusen) was treated dropwise with an about 70% strengthsolution of the binder (copolymer A2 from DE-A 43 24 801, the disclosureof which is hereby incorporated by reference herein in its entirety,copolymer Ia in the simultaneously filed application DE-P 195 15 919.5)or the mixtures (blend RD system), and mixing was performed thoroughlywith a spatula after each drop. The wetting point was reached when themass began to lump together and took on a dark appearance (Table 4).

                  TABLE 4                                                         ______________________________________                                        Pigmentability-wetting point of the binder systems (mass                        fraction in %, based on solids)                                                           Copolymer A2 Copolymer Ia                                                                              Blend                                     (comparison) (comparison) RD                                                 System DE-A 43 24 801 DE-P 195 15 919.5 system                              ______________________________________                                        Wetting point                                                                   Binder 19.1 17.6 15.8                                                         (mass fraction                                                                of solids)                                                                  ______________________________________                                    

Summary

As can be seen from Table 4, comparison polymer A2 consumed the mostbinder in order to reach the wetting point. This was followed by theextremely low molar mass copolymer Ia (comparison), although thisexhibited the problem of deficient drying in the clearcoat. The lowestbinder uptake was shown by the blend system with the epoxide-amineadduct, which also showed rapid drying in the clearcoat test.

Example IV Suitability Testing in Two-component Application

a) Coating Compositions

b) Adhesives or Sealing Compounds

The epoxide-amine adduct lb and its oxazolidine Ic (protectedepoxide-amine adduct of Ib) were taken individually as initial chargeand were tested for their suitability by slow addition of polyisocyanate(Desmodur® N 3390, Bayer AG, Leverkusen) under standard climaticconditions (Table 5).

                  TABLE 5                                                         ______________________________________                                        Suitability testing of epoxide-amine adduct/oxazolidine                         Reaction                                                                    ______________________________________                                        Standard climatic conditions 23° C.                                                      10%         85% rel atmos.                                      humidity                                                                    Epoxide-amine adduct Ib extremely rapid very rapid                            Oxazolidine Ic very slow moderate                                           ______________________________________                                    

Summary

As can be seen from Table 5, the epoxide-amine adduct Ib alone could beemployed preferably in the adhesives or sealing compounds industry,while the protected epoxide-amine adduct Ic (oxazolidine) would find itsprincipal application only in the coatings industry.

The invention has been described with reference to particularlypreferred embodiments and examples. Those skilled in the art willappreciate that various modifications can be made to the presentinvention without significantly departing from the spirit and scopethereof. In addition, all of the above-mentioned documents areincorporated herein by reference in their entirety.

What is claimed is:
 1. A mixture comprising:a) from 0.1 to 99.9% by massof one or more hydroxyl-containing co-polymers; and b) from 99.9% to0.1% by mass of one or more epoxide-amine adducts comprising at least20% by mass of a unit selected from the group consisting of (i)aliphatic epoxide and amine units,(ii) aliphatic epoxide units and (iii)amine units, said aliphatic epoxide units and said amine units eachcomprise at least one tertiary or quaternary carbon atom.
 2. The mixtureas claimed in claim 1, wherein the epoxide amine adduct is prepared byreacting:a) one or more aliphatic and/or cycloaliphatic monoepoxideshaving 7 to 33 carbon atoms; and b) one or more amine having at leasttwo primary or secondary amino groups and 2 to 30 carbon atoms, wherebysaid primary or secondary amino groups are not attached directly to anaromatic structure, and wherein at least 20% by mass of saidmonoepoxides is selected from aliphatic and cyclo-aliphatic monoepoxideshaving at least one tertiary or quaternary carbon atom.
 3. The mixtureas claimed in claim 1, wherein the epoxide amine adduct is prepared byreacting:a) one or more aliphatic and/or cycloaliphatic diepoxideshaving 8 to 50 carbon atoms; and b) one or more primary or secondarymonoamines having 4 to 30 carbon atoms, whereby said primary orsecondary amino groups are not attached directly to an aromaticstructure,and wherein at least 20% by mass of the monoamines is selectedfrom monoamines having at least one tertiary or quaternary carbon atom.4. The mixture as claimed in claim 1, wherein the epoxide amine adductis prepared by reacting:a) one or more aliphatic and/or cycloaliphaticmonoepoxides having 7 to 33 carbon atoms and b) one or more monoamineselected from primary and secondary monoamines having 4 to 30 carbonatoms, wherein said primary and secondary amino groups are not attacheddirectly to an aromatic structure,and wherein at least a % by mass ofthe monoamines is selected from monoamines having at least one tertiaryor quaternary carbon atom and at least b % of monoepoxides is selectedfrom aliphatic and cycloaliphatic monoepoxides having at least onetertiary or quaternary carbon atom, the sum of a and b being at least 20and a and b each being greater than
 0. 5. The mixture as claimed inclaim 2, wherein the monoepoxides are selected from glycidyl esters ofα-alkylalkanemonocarboxylic acids and glycidyl esters ofα,α-dialkylalkanemonocarboyxlic acids, said esters each containing 8 to21 carbon atoms.
 6. The mixture as claimed in claim 3, wherein thediepoxides are selected from the diglycidyl ethers of dihydric aliphaticalcohols and the diglycidyl esters of dibasic aliphatic carboxylicacids, said ethers containing 8 to 18 carbon atoms, and said esterscontaining 12 to 42 carbon atoms.
 7. The mixture as claimed in claim 4,wherein the monoepoxides are selected from glycidyl esters ofα-alkylalkanemonocarboxylic acids and glycidyl esters ofα,α-dialkylalkanemonocarboyxlic acids, said esters each containing 8 to21 carbon atoms.
 8. The mixture as claimed in claim 2, wherein thefunctionality of said adduct is reduced by partial or complete reactionof functional hydroxyl and amino groups of the initially preparedepoxide-amine adduct.
 9. The mixture as claimed in claim 3, wherein thefunctionality of said adduct is reduced by partial or complete reactionof functional hydroxyl and amino groups of the initially preparedepoxide-amine adduct.
 10. The mixture as claimed in claim 4, wherein thefunctionality of said adduct is reduced by partial or complete reactionof functional hydroxyl and amino groups of the initially preparedepoxide-amine adduct.
 11. The mixture as claimed in claim 8, whereinduring the reaction, the functional groups are blocked by reaction toform temporary protecting groups.
 12. The mixture as claimed in claim11, wherein the temporary protecting groups comprise one or moreoxazolidine compounds.
 13. The mixture as claimed in claim 1, whereinthe hydroxyl-containing copolymers are selected from acrylatecopolymers, polyesters and polyester-modified acrylate copolymers. 14.The mixture as claimed in claim 1, wherein the hydroxyl-containingcopolymers are selected from:aa) copolymers obtained by copolymerizationof at least two vinyl monomers of which at least one comprises at leastone hydroxyl group; ab) copolymers obtained by copolymerization of atleast two vinyl monomers of which at least one has at least one acidgroup, wherein said monomers are reacted, before, during or afterpolymerization, with at least one compound which reacts with the acidgroups to form an ester with the formation of at least one hydroxylgroup; and ac) copolymers obtained by copolymerization of at least twovinyl monomers of which at least one has at least one hydroxyl group,wherein said monomers are reacted, before, during or afterpolymerization, with at least one compound which reacts partly orcompletely with the hydroxyl groups to form an ester with the formationof at least one hydroxyl group.
 15. The mixture as claimed in claim 1,wherein a) comprises a mixture of hydroxyl-containing copolymers whicheach have a hydroxyl number of from 10 to 250 mg/g and of which at leastone copolymer has a weight-average molar mass of more than 3500 g/moland at least one copolymer has a weight-average molar mass of below 3500g/mol.